Well-cleaning process



C. LARSEN WELL cpaANlNG PROCESS Dec. 15, 1,925"

Filed June 27, 1924 marie; L a

attoz wmj Parenteel Dec.' 15, 1925.

CHARLES LARSEN, OF DENVER, COLORADO.

WELL-CLEANING PROCESS.

Application led June 27,

To all whom, itv may concern:

Be. it known that I, CHARLES LARSEN, a citizen of the UnitedStates.residing at Denver. the city and county of Denver and State of Colorado.have invented certain new and useful Improvements in Tell-CleaningProcesses; and I do declare the following to bc a -ency to` gum up andchoke, thereby greatly decreasing the amount of their production. Thisis one of the most serious problems confronting the producing end oftheindustry and many experiments have been made for the purpose ofproducingv some satisfactory method of cleaning the well and ofrestoring yit to production. It is not alone paraiiine that causes thesealing or choking of the 'well, but salt also adds to the'ditliculty.

In the past deparailining has been attempted in many different ways,some of which have been partially successful, but none of which havebeen generally adopted.

In a process of this type it is necessary to dissolve the saltas well asto melt the paraifine and to remove the salt and paraiine while they arein a fluid state, and this can only be accomplished when the pump lineand pumping apparatus is in place. I have found that if superheatedsteam at a pressure of substantially one thousand pounds is con- Dducted to the bottom of the well and there liberated, the heattransferred and liberated will soon raise the temperature of the wallsofthe well to such an extent that the parafline will-me1t'andflow outinto the sump where it is removed by 'the pump. The water which isformed from the condensed steam is a goodsolvent of salt 'and will causethe latter to go into solution, whereby it, as well as the paralhne,will be removed by the pump. Actual experiments have shown that wellswhich have been treated for jless thantwenty-'four hours, have had theirproduction increased approximately eighty-live per cent.

The steam is introduced into the well and 19,24. serial No. 722,s1s.

,conducted to the bottom by means of a small pipe located within alarger pipe, from the walls of which it is spaced so as to be entirelysurrounded by an air space that'serves as a heat insulator. A speciallitting is provided at the lower end of the larger pipe, which forms aseal between it and the smaller pipe, whereby liquid Vis prevented fromentering the air space between the pipes. v

In order to carry out my process successfully, I employ an apparatuswhich I will now describe in detail, reference for this purpose beinghad to the accompanying drawsoy ing in which the apparatus .is shown ina general way, and in which:

Fig. 1 is a vertical section through a well and shows the location ofthe pump line, the steam line and the boiler; andy Fig. 2 is a sectionthrough the lower end of the steam line and shows the special fitting.

Numeral'l represents an oil well whose bottom has been enlarged byshoot-ing into a chamber 2, which varies in size, but which is usuallyabout twenty feet in diameter. After a well has been in operation forsome time, the parafline will gum or clog the pores in the sand,producing astratum 3 which is practically impervious and whichthereforeprevents oil from the surrounding sand to flow into the well. vThisfsealing action is further aggravated b the presence of salt, whichprecipitates an forms a crust onthe inner surface. The ultimate resultof this sealing action is to render the well entirely nonproductive.

The pump line 4, with its working barrel 5 and pumping jack 6 is ofordinary construction, and is not interfered with or al-` tered in theleast. For the purpose of generating the steam I have provided a boiler7 which, together with the remaining parts of the apparatus,-is'specially built of bronze and Monel steel so as'to enable it toWithstand the terrific heat landl yressure. The heat is derived from anoil last which is produced by means of well known apparatus. The' steamis conducted by means of a three-quarter inch, gt/f) pipe 8 (from theboiler), which exten s downwardly within the two inch (2) pipe 9. Thelower end of pipe 9 is provided 'with an ordinary hydraulic coupling 10,to which isl threadedly connected a special fitting 11. This fitting hasan axial opening 12 approximaly Aone and one-half inches (1l/2)indiameter, extending substantially one-halt1 fthe' length thereof,Another opening 13 co-axial with opening 12, but of a smaller diameter(about one inch) extends the remainder of the le ngth,of the tting. Theshoulder 14, which joins the inner surfaces of the two openings, isinclined at degrees and forms vents water or other liquid from cnteringthe space between the pipes and at the same time permits the withdrawalof pipe 8. Secured to the part 16 is a nozzle 17 which is provided withvperforations 18.

The lower'end ofthe fitting 11 is threaded,

as indicated by numeral 19,'for connection of an anchor in case thisvshould be necessary., l f When the partsare in place in the manner shownand described, steam is vgenerated in the boiler 7 and raised to apressure of about 1000 pounds per square inch and superhveatedto elevenhundred de ees Fahrenheit. This intensely hot, hig pressure .steam ispermitted to flow through-pipe 8 land enters the well through theopenings 18 in the nozzle 17. The pump is kept in constant'operationwhile the process is carried out and serves to remove the moltenparaiine from the walls.

b By means of theprocess outlihed above, it

will become possible to restore to production a4 large percentage of themany thousand wells that have become partially or entirely choked bvparaiiine or salt and thereby make available a large amount of oil thatat present is unattainable.

This application is a continuation in part of my (zo-pendingapplication, Serial No. 664,130', filed September 21, 1923.

Having now described my invention, what I claim as new is:

l. A method of cleaning oil wells, which consists in generating steamata pressure of substantially one thousand pounds per square inch andconducting' the same to the bottom of a Well where it is permitted toexpand and liberate its heat whereby the Walls of the well become heatedsufficiently to Vmelt any solidified paraifine, and whereby the water ofcondensation will cause solublefmatter to enter ntosolution, a-ndsimultaneously removing the liquids from the well.

2.'A method of cleaning oil wells, which consists in generating steam ata pressure of substantially one thousand pounds per square inch andsuperhated to eleven hundred degrees Fahrenheit and conducting the sameto the bottom of aJ well where itis permitted to expandand liberate itsheat whereby the walls of the well become heated suiciently to vmeltAany solidified paraliine,

Iand whereby the water `of condensationwill cause soluble nfatter toenter into Solution,

and simultaneously removing the liquids from 'the well. p

In testimony whereof I affix my signature.`

CHARLES LARSEN.

